this study was not done with chocolate, but with lower-calorie, nutritionally balanced drinks rich in cocoa flavanols.

The Express includes quotes from the research leader, Dr Giovambattista Desideri, which are more cautious than that front page headline:

"It is yet unclear whether these benefits in cognition are a direct consequence of cocoa flavanols or a secondary effect of general improvements in cardiovascular function. Larger studies are needed to validate the findings..."

But the Express does not include this quote:

"Based on the current explosion of obesity, which is particularly evident in children, we should be careful when recommending chocolate ingestion to our patients...In real life, the progressive increment of body weight due to an unbalanced diet is likely to counterbalance the positive effects of cocoa on vascular function."

There's an important quote - in the final paragraph of the article, of course - from Alzheimer's Research UK:

“It would be useful to see more long-term studies to investigate the lasting effects. Ultimately we would need to see the results of large-scale trials to know whether cocoa flavanols could help prevent or delay dementia.”

"the lifestyle intervention with the strongest science behind it is
physical exercise. I would recommend physical exercise before
I would recommend chocolate...the study is interesting but requires replication before it can be taken seriously."

I have to say, that front page is almost the archetypal Express front page, it almost has it all: Murdered woman, Dubious medical advice, celeb gossip and moaning about the weather. All it needs is a picture of royalty and some kind of comment on housing prices and you could substitute it for any Express front page for the last few years!